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We need to eliminate NVA of retapping for threaded inserts

October 12, 2011

Hi I am KK, I work for precision sheet metal company as QA Engg, we manufacture sheet metal parts from raw sheets, we do carry some of the operation as below, like

CNC Blanking(Laser cutting/Punching)
CNC Bending
Inserting
Drilling/taping
Plating/Coating
etc

We have problem at plating, i.e., some of the components have below process like

Laser cutting--->Bending--->Inserting--->Plating--->Retapping of Inserts--->Packing--->Dispatch.

Here the constant is we have to re-tap the inserts (duly plated) which undergo plating process (raw part plating) & cause deposition of plating on the inserts missing Thread gauge. Not to answer or answer negative, I would be thankful if anyone could help me out to overcome this situation and avoid retapping of the parts after plating, which is a total NVA.
Any guidelines to prevent excessive deposition on thread at the time of plating will be appreciated.

Impt: Pressing inserts before bending or sometimes after bending & before plating is necessary, because customer designs sometimes are so complex, where such above operations becomes necessary.

KK Prabhu
plating shop employee - Ponda, Goa, India

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October 13, 2011

Can you use plugs? Silicon pull plugs work well.

Do the inserts have to be plated? I assume not.

You could try using long wood Q-tip [affil links] and put a light coat of hot wax on the inserts. It should be thin enough that you do not have to remove it and thick enough to prevent plating.

James Watts
- Navarre, Florida